Leak detection systems incorporate the injection of tracer fluid into a tank and the use of sensors outside the tank to detect for the presence of leaked tracer. Most detection systems require that operating fluid be first removed entirely from the tank, resulting in downtime and cost to the tank operator. Some detection systems are able to work while operating fluid is present and the tank is in operation, for example the systems disclosed in U.S. Pat. Nos. 5,767,390, and 4,709,577. However, such systems usually require a mixing device for dispersing tracer gas uniformly throughout the fluid and have lengthy response times.
Leak detection systems may incorporate permanent cable sensors along a length of a pipeline or underground tank that allow fluid diffusion along the length of the cable for detection of leaks.